Conventionally, a seat slide mechanism comprises two seat slides, one on each side of the vehicle seat, each seat slide comprises a lower rail adapted to be fixed to the vehicle floor and an upper rail adapted to carry the seat. Each upper rail is capable of movement in a fore-and-aft direction relative to the lower rail. A locking mechanism is further provided for securing the upper rail and seat in the desired position with respect to the lower rail and the vehicle floor, the locking mechanism being releasable normally by a handle to allow any required adjustment of the fore-and-aft position.
It is also known, particularly in the case of two-door vehicles, to provide the front seat slide with a memory system, operable by a suitable lever, e.g. comprising the seat squab, which overrides the locking mechanism, thus allowing the front seat to be moved forward and providing easy access for a person to a rear seat. The same memory system is also operable on returning the seat squab to its upright position to enable the seat to be moved back to its original position as previously set by the front seat occupant.
However, some such systems are relatively complicated and therefore expensive to manufacture. Some systems suffer from the disadvantages that they sometimes operate incorrectly or out of sequence. Examples of such systems are disclosed in U.S. Pat. No. 4881774 and EP-A-0411850, the latter publication disclosing a vehicle seat slide mechanism.